Sewing machine



J. LEATHEM S EWI NG MACHI NE Aug. 11, 1925.

oiginal Fild Sept. 1a 1920 l 4 sheets-sheet 1 Aug. 1l, 1925.

J. LEATHEM SEWING MACHINE 4 Sheets-Sheet 2 Original Filed Sept. 15, 192Q J' LEATHEM SEWING MACHINE 4 sheets-Sheet s Original Filed Sept. 15, 1920 Aug. 11, 1925.

J. LEATHEM SEWING MACHINE Original Filed Sept. 15, 1929 4 Sheets-Sheet 4 Patented ug., ll, 1925.

saresti erica.

Jai/ins nnnrrinivi, or LEBANON, PENNSYLVANIA.

SEWING MACHINE.

Original applicati-on filed September l5, 1920,\Seria1 No. 410,472. Patent No.1,464,081, dated August?,

To all ywhom t may concern.'

lle it known. that l, JAMus Lauri-IEM, .a citizen of the United States, and a resident of l'iebanon, in the county yof Lebanon and Stat-e of Pennsylvania, have invented certain .new and useful Improvements in Sewing Machines, of which the following is a speci fication.

rlhis invention relates to sewing machines, employing a needleI having reciprocating as well as oscillating movements such as are used in the stitching of hein stitched seams and the objects of the invention are to simplify and improve the construction of such machines and incr-ease their efficiency of operation so that the same can be run at very high speeds.

The accompanying drawings illustrate one embodiment of my invention, in the several figures of which like parts are similarly designated.

In the drawings Figure 1 is a front elevation of a sewing machine made in accordance'with the present invention, shown partly in section and parts broken away for clear-ness of illustration.

Figure 2 is a bottom view of the sewing machine shown in Figure 1.

Figure 3 is an end view, partly in section and with parts broken away of the sewing machine shown in, Figure l.

Figure d is a sectional view, with parts broken away on the line 4--1 of Figure 3.

Figure is a sectional view, with parts broken away on the line 5`5 of Figure 1.

Figure 6 is a sectional view, with parts broken. away on the line 6 6 of Figure 1.

Figure 7 is an enlarged sectional view, with parts broken away of the rear side of the head of the machine.

Referring to the drawings, 1 designates a bed plate; 2 an overhanging hollow arm in which is mounted needle bar actuating shaft 3 by means of bearing blocks 4. The forward end of the actuating shaft 3 has rigidly secured thereto one end of a crank arm 5 to the other end of which is rotatably mounted one end of a short link 6 the other enid of which is rotatably mounted upon an adjustable stud bearin 7 secured to a needle bar 8 suitably mounted in the overhanging arm, the. needle bar being reciprocated by Divided and this application filed January 20, 1922.

Serial No. 525,257.

the oscillations of the actuating shaft to which it is connected as follows The rearward en'd of the actuating` shaft 3 has adjustably secured thereto one end of'a crank arm 9 to the other end of which is rotatably mounted one end of a connecting rod 10the other end of which is rotatably mounted oni a crank 11 forming part of a main driving shaft 12 mounted in suitable bearing blocks 13, 14 and 15 secured to the bottom of the bed plate.

rllhe rotation of the main driving shaft 12 through the medium of a suitable pulley 16 acts to reciprocate the connecting irod 10 which oscillates the actuating shaft 3 and it in turn acts through the crank arm 5 link 6 and stud bearing 7 to reciprocate the needle bar 8.

rlChe lower end of the needle bar 8 is provide-d with a slotted bearing block 17 in which is pivotally mounted by means of a tapered pin 1S the lower end of a needle actuating lever 19 having at its lower end preferably integral therewith, a needle holder 2O for holding a needle 21. The needle bearingv block 17 is also provided with means for holding a piercer 22. The upper end of the needle actuating lever 19 is pivoted to a cross head 28 which is arranged to slide in a suitable groove or raceway 24 in a needle oscillating lever 25, in the present instance made L shape. The upper end of the needle oscillating lever 25 is arranged to lit in a groove 26 in the forward endV of the arm in which it is pivoted by means of a pin 27, the lower end of the lever 25 being also arranged to lit in a groove 28 in the. forward end of the arm, the same being pivotally connected, by means of a pivot pin 29, t the forward end of aI link 30. he reari ld end of the link 30 is pivotally connected, by means of a pivot pin. 31, to the upper end of a'slotted segment lever S2, the lower end of which is pivoted to the upright portion of the arm by meansof a pivot pin 33. A segmental slot 34k in the lever 32 is arranged to adjustably engage one end of a link 35 by means of a pivot bolt 36, the other end of the linkbemgpwotally connected b-y means of a pivot pin 37 to one end of a short crank arm 38', the lower end of which is rigidly connected to one end of a shaft 39 rotatably mounted in the upright portion of the arm, the backwardly eX- tending portion of which is suitably recessed together with the bed plate to permit of free movement of a crank arm the upper end of which is rigidly Ysecured to the shaft 39 adjacent its rear end. The lower end of the crank arm 40 is provided with a roller 41 arranged to engage a cam groove 42 in a circular cam 43 secured to an auxiliary shaft 44 mounted in the bearing blocks 13 and 14. lrtounted on the auxiliary shaft 44 is a gear 45 which is arranged to be engagedby a pinion 4G mounted on the main driving shaft 12.

The rot-ation of the main driving shaft 12 acts through the pinion 46, gear 45, cam 43 and connecting parts to oscillate the needle oscillating lever 25 whose oscillations act to oscillate the needle actuating lever 19 and thereby the needle 21 as the needle bar is reciprocated.

The oscillations of the needle can be regulated by setting the pivot bolt 36 at different positions in the segmental slot 34, any ordinary throw of the needle can be ob tained in this manner, further regulations of the throw of the needle can of course be obtained by varying the cam groove in the cam 43.

In the present instance the looping mechanism comprises a rotary hook or loop taker 47 having a vertical shaft 48 rotatably mounted in a bearing block 49. The shaft 4S is provided intermediate of its length with a bevel pinion 50 which meshes with a bevel gear 51 mounted on the main driving shaft 1 2 adjacent the end thereof. The relative sizes of the bevel pinion 50 and the bevel gear 51 to form a hemstitch being such as to impart two rotations to the loop taker 47 to each complete stroke of the needle bar.

In accordance with the present invention Y' the cam groove 42 in the cam 43 is cut to oscillate the needle 21 at proper intervals to form a hemstltch. In the present instance the cam groove 42 1s cut to give a substann tially straight up and down movement to the needle when a stitch 1s made on the hem fold of the material, and to oscillate the needle when stitches are made oft the hem fold, the cam groove being suitably cut to n oscillate the needle to place two stitches otl' the hem fold to one on.

In that the needle 21 is moved substantially straight up and down when placing a stitch on the hem fold the needle thread v does not bind and break during this portion the binding of the needle thread between the needle and the material.

After the needle 21 has been actuated by the cam groove 42 on the cam 43 to place a stitch on the hem fold, the cam groove 42 on the next downward movement of the needle acts to oscillate the needle to place a stitch off the hem fold. After the needle has passed through the material to place the stitch oit the hem fold the cam groove 42, on the further downward movement of the needle acts to oscillate the needle toward the rotary hook or loop taker 47 to permit the needle thread to be engaged thereby, in which position the needle is moved by the action of the cam groove 42 substantially straight up and down at the end of its downward movement and at the beginning of its upward movement. On the further upward movement of the needle the cam groove 42 acts to again oscillate the needle away from the loop taker to permit the needle to come out of the material at substantially the same point where the needle entered the material olf the hem fold, so as to obviate any tendency to bind the needle thread between the needle and the material to cause the thread to break.

After the needle 2l has been oscillated by the action of the cam groove 42 to place one stitch oft the hem fold the cam groove 42 again acts in exactly the same manner to place another stitch oif the hem fold, which operation is followed by another series of operations to place another stitch on the hem fold and two ofi', as before described.

The oscillations of the needle back and forth by the action of the cam groove 42 every time a stitch is placed off the hem Atold so that the needle enters and leaves the material at substantially the same point obviates any tendency to bind the needle thread between the needle and the material to cause the thread to break even at the highest speeds.

Then the machine is run at very high speeds it is extremely important that there be no binding of the needle thread as it passes through the material, as the slightest binding of any kind will cause it to break; while it is true that the needle is ordinarily provided with a longitudinal recess on both sides, these recesses act to prevent binding only when the needle is reciprocated straight up and down in the material; when however the needle is oscillated to place a stitch ott' the hem fold the movement of the needle inward to draw the needle thread into engagement with the hook or loop taker, crowds the material up against the needle in suc-h a manner as to bind the needle thread when the needle is withdrawn from the material if this crowding of the material is not relieved.

ln accordance with the present invention the crowding of the material against the needle as the needle is withdrawn after placing a stitch ott the hem fold is accomplished,

tit)

as above described; by cutting the cam groove 42 in the cam 43 so that the needle leaves the material at substantially the same point as the needle entered the material, or at such a point as near where the needle originally entered as to be beyond where the material will bind or break the needle thread. The crmvding of the material against the needle is not a serious matter when the machine is run at comparatively low speeds but when the machine is run at very high speeds it is absolutely essential that this crowding of the material which acts to hind the needle thread be obviated.

ln the present instance the feeding mechanism comprises a feed bar 52 having suitable feed points 53 situated on the top surface of a recessed feed dog 54 secured to said feed bar. @ne end of said feed bar is pivoted, by means of a bearing pin 55, to the upper ends of two short arms 5G, the other ends of which are secured to a rock shaft 57 rotatably mounted on bearing pins 58 secured to lizearing blocks 59 and 60 secured to the bottom of the bed plate. The roclr shaft 5'? has adjustably secured thereto a slotted arm 61 in which is adjustably secured thereto a slotted arm 61 in which is adjustably secured one end of a link 62 by means lof a pivot bolt 63 the other end of the link (32 being pivoted to one arm of an l. shaped lever 64 the centre of which is secured to one end of a sleeve (l5 rotatably mounted on a shaft 66 secured to the bearing blocks 13 and 14. The other arm of the l. shaped lever G4 is provided with a roller (57 which engages a cam groove G8 situated on the side `of the gear mounted on the auxiliary shaft 44.

The rotation of the main driving shaft 12 acts through the pinion 4G, gear 45, cam groove (i8, roller ci' and connecting parts to move the feed bar 52 and with it the feed dog 54 baclr and forth at stated intervals to feed the material backward or forward as i'nay he required. ln the present instance the cam groove (58 is arranged to move the feed dog 54 back and forth for every coniplete stroke of the needle har. rlfhe back und Yforth moven'ient of the feed dog is regulated by adjusting the pivot boit (33 in the slotted arm (il to give any desired feed nurvei'ncnt of the feed dog.

The 'other end of the feed bar 52 is slotted to receive a cross head (l) which is pivot-ally secured to one end of a short arm TO the other end of which is secured to a rock shaft Tl rotatably mounted on bearings pins 79, secured to bearing blocks 73 and 13 securedto the bottom of 'the bed plate. rl`he rock shaft (1 has secured thereto one end of a short arm 74 the other end of which is' provided with a roller 75 which engages a cam groove ZG iu a segmental cam 7'( secured to a. roclr shaft 78 rotatably.mounted on bearing pins 79 secured to bearing blocks 73 and 13. The segmental cam 77 is provided with a slot 80 which engages a cross head 81 pivoted on a disk 82 secured to the end of the auxiliary shaft 44.

rl"he rotation of the main driving shaft l2 acts to rotate the auxiliary shaft 44 and it acts through the cross head 81, segmental cam 7?' and connecting parts to depress the feed bar 52 and with it the feed dog 54 at stated intervals. The feeding mechanism above described is arranged to feed the material forwardly two steps to one step rearwardly, the needle being oscillated to place stitches on and olf the hem fold of the material to make a hem stitch substantially as follows The needle makes the first stitch olf the hem fold of 'the material; the material is then fed rearwardly; the needle new makes a second stitch olf the hem fold Iof the material; said material is now fed forwardly; the needle then makes a third stitch on the hem fold of the material; the feed dog is rapidly depressed, moved rearv-ardly and then slowly upwardly to engage the material; the material is now fed forwardly. The operation of the machine continues, the movements of the aforesaid parts proceeding as follows The needle makes first stitch olf the hem fold of the material; said material is now fed rearwardly; the needle makes a second stitch olf hem fold of material which registe with the first stitch olf the preceding series of three stitches; said material is now fed forwardly; the needle then makes a third stitch on the hem fold of the material; the feed dog is rapidly depressed, moved rearwardly and then slowly upwardly to engage the material; whereupon the material is againl fed forwardly and the above operations are repeated.

ln accordance with the present invention the upward and downward movement of the feed dog 54 into and out of engagement with the material is regulated to give a relatively slow upward movement of the feed dog, as it engages the material, with a corresponding rapid downward movement of the feed dog as it disengages the material.

The relatively slow upward movement of the feed dog acts to force the material against the bottom of a suitable double presser foot 83 with little or no jar and according'ly without injury to the material, it being important at high speeds to avoid the jar incident to a too rapid engagement of the feed dog with the material which would act to force the material against the bottom of the presser footin many instances with sufficient force to cut the same.

rlhe corresponding rapid downward movement of the feed dog acts to disengage the material instantly without jar or shock lll() allowing the time thus saved to be used on the relatively slow upward movement of the feed bar.

By referring to the drawings it will be seen that when the cam groove 76 acts to depress the feed dog 54 the cross head 81 on the disk 82 is moving in that portion of the slot 80 of the segmental cam 77 which is adjacent the rock shaft 78, which acts to give a rapid downward movement to the feed dog; when however the cam groove 76 acts to raise the feed dog, the cross head 81 on the disk 82 is moving in that portion of the slot 80 of the segmental cam 77 which is away from the .rock shaft 78 which acts to give a relatively slow upward movement to the feed dog.

In the present instance the double presser foot 83 comprises two presser shoes 84 each of which is suitably pivoted midway of their length to the lower curved ends of shoe arms 85 the upper ends of which are secured to the lower ends of independent presser foot bars 86 each of which is slidably mounted in the end of the overhanging arm 2. The upper end of each of the presser foot bars are preferably made hollow and arranged to enclose coiled springs 87 arranged to be engaged by pins 88 pressed downward by means of suitable caps 89 which screw into the arm 2 to force the shoes 84 into engagement with the material on the feed dog. then in the operation of the machine the feed dog is lowered the overhanging sides of the presser shoes rest upon the feed plate 90.

The presser shoes 84 are arranged to act on the material entirely independent of each other but the same are arranged to be lifted when not in use by means of a latch 91 pivoted to the arm 2 which engages a projection 92 secured to a double collar 93 mounted on both presser foot bars and arranged to be secured to one and slidably mounted on the other. A similar double collar 94 is also provided which is mounted on both presser bars and spaced away from the double collar 93 the same being secured to the opposite presser foot bar and slidably mounted on the other so that the latch 91 will operate both presser shoes at the same time leaving the presser shoes when in operative position to act independently, the double collars 93 and 94 acting to brace the presser foot bars one against the other.

1t is to be noted that the presser foot bars 8G are slidably mounted in the end of the arm as nearly adjacent the needle bar 8 as possible, in order to give as nearly as possible a direct upward thrust to the presser bars when the presser shoes are engaged on the upward movement of the feed dog. The mounting of the presser foot bars so nearly adjacent the needle bar is made possible by the fact that the needle bar is reciprocated by the rocking of the actuating shaft 3, less space being required for a reciprocating connection than otherwise would be the case if the actuating shaft 3 was rotated. rlfhis arrangement of the presser bars prevents excessive vibration of the presser foot and enables the machine to be run at very high speeds with a uniform feeding of the material.

T he take up mechanism comprises a take up arm 95 arranged to extend upward through a slot 90 in the bed plate, the lower end of said take up arm being integrally secured to a short shaft 97 rotatably mountet in the bearing block 14. The shaft 97 has secured thereto one end of a short arm 98, the other end of which is pivoted by means of a ball joint 99 to one end of a link 100 the other end of which is pivoted by means of ball joint 101 to the end of an adjustable arm 102 secured to a short shaft 103, rotatably mounted in the bearing block 14. T he end of the shaft 103 which projects beyond the end of the hearing block 14 is secured to one. end of a guide rod 104 upon which is slidably mounted a slide sleeve 105 having an extended portion 100 which is pivoted by means of a pivot pin 107 to an extended portion 108 on the lower end of the connecting rod 10.

The rotation of the main driving shaft 12 in a clockwise direction acts through the medium of the slide sleeve. 105 to oscillate the guide rod 104 which acts through connecting parts to oscillate the take up arm 95. The position of the slide sleeve 105 on the end of the connecting rod adjacent the crank 11 with the corresponding position of the connecting parts acts to give a rapid movement to the take up arm when the same is moving from left to right to take up additional thread and a relatively slow movement when the take up arm is moving from right to left to let out the thread, together with a gradual acceleration of the take up arm near both ends of its movements.

1n other words, the motion of the take up arm is slow while the hook or loop taker 47 is taking the loop of the needle thread which takes place when the take up arm is moving from right to left, while for drawing the stitch tight, which takes place when the take up arm is moving from left to right, the movement of the take up arm is extremely rapid, lt will be observed that the slide sleeve 105 is at the lower portion of the guide rod 104 adjacent the shaft 103 when the take up arm is moving' from left to ri ght and also near both ends of its movements, permitting relatively fast movement of the take up arm during this time, when however the slide sleeve 105 is at the upper portion of the guide rod 104 the take up arm is moving from right to left, permitting relatively slow movement of the take up arm during this time.

The machine above described is capable of ruiming at the rate of forty-five `hundred revolutions a minute upward to five thousand revolutions a minute with practically no vibration.

lVhile the invention has been described with particular reference to the details of construction, the same. is not to be considered as limited thereto, as many changes can be made and still fall within the scope of the invention set forth in the following claims.

Vhat I cla-im is 1. In a sewing machine a feed dog, operating means therefor including a cam plate adapted to oscillate about a pivot, said plate being provided with a cam slot; a member engaging in said cam slot, a shaft integral with said member and adapted for oscillation about its axis; a feed dog actuating member fixed to said shaft and engaging said feed dog, said cam mechanism being arranged to move the feed dog slowly upward and reversely with a rapid downward movement thereof. 'l

2. In a sewing machine feed mechanism, the combination with a revoluble drive shaft, of an auxiliary shaft driven thereby and carrying a cross head, a rock shaft carrying a plate having a cam slot engaged and oscillated by said cross head, a pivoted angle lever, cam means on the auxiliary shaft for moving the angle lever, a rock shaft having an operative connection with said angle lever, a third rock shaft having an arm engaged within said cam slot, a feed bar carrying a feed dog, an arm on the second named rock shaft connected with the feed bar, and an arm on the last named rock shaft operatively engaging the adjacent end of the feed bar.

3. In a sewing machine feed mechanism, the combination with a revoluble drive shaft, of an auxiliary shaft driven thereby, a disk on the auxiliary shaft carrying a cross head, a rock shaft carrying a segmental cam member operatively connected with the cross head for oscillation thereby, a second rock shaft, cam means on the auxiliary shaft for rocking the second named rock shaft, a third rock shaft having an operative connection with said segmental cam member, a. feed bar having a slot, an arm on the second named rock shaft connected with one end of the feed bar, a feed dog on the feed bar, and an arm on the last named rock shaft connected within the slot in the other end of the feed bar.

4. In a. sewing machine feed mechanism, the combination with a revoluble drive shaft, of an auxiliary shaft driven thereby, a disk on the auxiliary shaft carrying a cross head, a rock shaft carrying a segmental cam member operatively connected with t-he cross head for oscillation thereby, a second rock shaft, cam means on the auxiliary shaft for rocking the second named rock shaft, a third rock shaft having an operative connection with said segmental cam member, a feed bar having a slot, an arm on the second named rock shaft connected with one end of the feed bar, a feed dog on the feed bar, an arm on the last named rock shaft connected within the slot in the other end of the feed bar, and means for varying the connection of the auxiliary shaft cam actuated means with the second named rock shaft.

5. In a` sewing machine, the combination with a revoluble drive shaft, of an auxiliary shaft driven thereby, a pair of rock shafts arranged at opposite sides thereof, cam means driven by the auxiliary shaft for oscillating said rock shafts, a feed bar at right angles to said shafts carrying a feed dog, an arm on one rock shaft pivotally connected with one end of the feed bar, and an arm on the other rock shaft pivotally and slidably connected with the other end of the feed bar, the cam means for operating one rock shaft comprising an arm thereon, a cross head carried by the auxiliary shaft, a rockable member having a slot within which the cross head operates and having a second slot receiving said arm.

6. In a sewing machine, the combination with a revoluble drive shaft, of an auxiliary shaft driven thereby, a pair of rock shafts arranged at opposite sides thereof, cam means driven by the auxiliary shaft for oscillating said rock shafts, a feed bar at right angles to said shaftcarrying a feed dog, an arm on one rock shaft pivotally connected with one end of the feed bar, and an arm on the other rock shaft pivotally and slidably connected with the other end of the feed bar, the cam means for operating one rock shaft comprising an arm thereon, an angle lever pivotally mounted and having one arm connected therewith, and a cam disk on the auxiliary shaft engaging the other arm of the angle lever, the cam means for operating the other rock shaft comprising an arm thereon, a cross head carried by said cam disk, and a pivoted member having a slot receiving said cross head and having a second slot receiving said arm.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

' JAMES LEATHEM.

Writnesses:

L. F. GRIMEs, L. RUTH GrRIMEs.I 

